package javabase.biji;

/**
 * @Auther: luzhanshi
 * @Date: 2021/2/2 - 02 - 02 - 10:42 
 * @Description: javabase.biji
 * @version: 1.0
 */
public class _25包装类 {
    public static void main(String[] args) {
        Integer integer = Integer.valueOf("111");
        int i = Integer.parseInt("222");
        Integer iii = null;
        iii += 300;//默认调用iii.intValue()

        System.out.println(iii);//NullPointerException

    }


}
